Glossary of Fine Art Conservation & Restoration Terms
Fine Art Conservation & Restoration Terminology
Abrasion
Any alterations to the surface of artwork resulting from friction, scraping, or inappropriate cleaning methods.
Absorption
a) The process of one substance penetrating another through osmosis, solvent action, or capillary action. b) The absorption of light leading to a reduction in the intensity of pigment layers, for example.
Accretion
Unintended deposits of extraneous matter not originally part of the artwork, such as specks of dirt, dust, or dried liquids.
Adsorption
The attachment of liquid or gas molecules to solid or liquid surfaces through physical or chemical interactions upon contact.
Aging/Cracks
Cracks resulting from the aging process, stemming from prolonged exposure to mechanical, environmental, and other stressors. These fissures can traverse all layers of the artwork, originating from the support structure.
Auxiliary Support
Generally referring to a stretcher or strainer, an auxiliary support serves as the secondary structure for a painting or other art piece, providing a framework for canvas stretching.
Backing Board:
A rigid backing board is affixed to the rear of the auxiliary support to safeguard and reinforce or encase the artwork.
Beva 371:
Beva 371 serves as a specialized adhesive designed for use in art conservation. Its applications are versatile, including mounting canvas onto wood, textiles onto textiles, paper onto canvas, and more. Application methods range from roller and brush to thinned application via spraying. Its reversibility is achieved through heat or solvents.
Binder:
A substance that creates a cohesive film, binding the pigment particles in paints together, such as vegetable gum in watercolor paints or oil in oil paints.
Binding Agent/Material:
This encompasses any substance or product utilized to unite disparate or akin materials. For instance, linseed oil or alternative oils act as binding agents, amalgamating pigments and constituting the pigment layer. In situations involving the adhesion of materials or gluing, it is referred to as a bonding agent.
Blanching:
Blanching occurs when there's a breakdown in the connection between the binding agent and pigment particles. This disruption alters light refraction within the layer, leading to discoloration. Typically triggered by exposure to humidity and condensation.
Blistering:
Blistering refers to the separation of layers induced by heat, also known as burn blistering.
Bloom:
Bloom manifests as a yellowish, white, or bluish-white haze on the surface, resulting from ground and paint components migrating to the painting's surface.
Buckling:
Buckling involves the lifting of ground and paint layers, forming ridges. Typically caused by compression or pressure, it's often associated with flaking, cleavage, and cracks.
Canvas:
A fabric support for paintings, typically woven from fibers like hemp, cotton, ramie, jute, linen, or blends thereof.
Chalking:
The formation of a powdery deposit on a paint layer due to inadequate binding medium or exposure to outdoor weather conditions.
Chip:
A fragment of material, such as wood, ground, or paint layer, that has broken away from the artwork.
Cleavage:
The separation of a layer within the artwork.
Cockle:
A bulge or fold creating a wrinkled or creased surface.
Concentric Cracks:
Cracks arranged in circular or cobweb patterns, often caused by pressure or impact.
Corner Draws:
Ripples extending from the corners of the canvas.
Craquelure:
A network of cracks in a paint layer.
Crazing:
A) The formation of a network of opaque cracks in a layer of varnish. B) Cracking within the pigment or paint layer, similar to blanching.
Cup (or Cupping):
The upward turning of crack edges, forming "cups" as a result of aging.
Deformation:
Alterations to the original shape of the support, including depressions, bulges, and cockling
Delamination:
Separation of layers within an artwork, often seen in paintings or prints.
Dent:
A concave indentation on a surface, caused by pressure or impact.
Diagonal Cracks:
Cracks often seen in the corners of paintings due to inconsistent keying or corner impacts.
Dispersion:
The even distribution of particles from one substance within another.
Drying Cracks:
Cracks that develop during the drying process of paint layers, typically curved and wide.
Drying Oils:
Oils like poppy-seed, walnut, and linseed used in European easel painting, which oxidize and dry when exposed to oxygen.
Edge-Strip:
A protective strip attached to a painting's outer edges, extending above the front surface.
Encaustic:
A painting technique using pigments or paints mixed with hot wax.
Examination:
A visual inspection of a work of art.
Facing:
A protective covering, often Japanese paper, applied to delicate paintings.
Fading:
Loss of color intensity or vibrancy in pigments, typically caused by exposure to light or other environmental factors.
Feather Cracks:
Fine cracks resembling feathers, caused by contact with the back of the painting.
Fill/Filling:
Replacement of lost material or paint layers to level with the surrounding surface.
Flaking:
The detachment of fragments of ground or paint layers from the layer below.
Glaze:
A transparent layer of oil or resin applied to a painting's surface.
Gouache:
An opaque watercolor paint.
Grime:
Accumulation of dirt on or ingrained into the artwork's surface.
Ground:
An opaque preparatory layer applied to the support material to create a painting foundation.
Heat/Vacuum Table:
A heated surface with suction used in conservation processes.
Impasto:
The technique of applying paint thickly to create texture.
Imprimatura:
A thin layer of paint applied over the ground to provide a base tone for a painting.
Indicator:
A material that changes color to indicate a chemical reaction.
Infrared Reflectography:
A technique using infrared radiation to reveal preliminary drawings and other hidden elements.
Inpainting:
The application of new paint to areas where the original color is missing.
Japanese Paper:
Traditional Mulberry paper used in conservation and repair of paper-based artworks and books.
Key (or Keying):
The insertion of a small wedge or block, known as a corner key or tightening key, into the inside corners of a stretcher to adjust tension or prevent canvas sagging.
Layer Separation:
The separation of various layers within a painting (such as ground, paint layer, varnish) due to specific external or internal factors.
Lifting:
The detachment of one layer from another within the artwork.
Liner:
The inner section of a frame that lines a painting, made independently of the frame structure.
Lining:
Also known as "relining," a reinforcement technique involving the gluing of cloth pieces to the rear of a textile support surface.
Loose Lining:
A method where fabric is stretched behind but not attached to a canvas painting, providing support and protection.
Loss/Lacuna:
An area of missing paint or paint and ground layer due to damage or deterioration.
Marouflage:
The process of adhering a canvas to a rigid material, such as a panel or wall.
Mechanical Cracks:
Cracks with sharp edges caused by excessive stress or movement within the layers of the painting.
Medium:
A substance mixed with paint to modify specific characteristics like flow, texture, drying time, or finish.
Mending Plate:
A custom-shaped metal plate used to secure a painting within a frame.
Nap-Bond Method:
A lining technique where the lining canvas is attached to the original canvas with adhesive applied to only a few small areas, rather than covering the entire canvas.
Neutral Retouching:
A retouching method where a missing paint area is filled in with a neutral tone matching the original surroundings.
Normal Retouching:
A retouching process involving the application of fine dots and strokes to damaged areas, making the paint layer appear uniform after filling.
Overpaint:
Additional paint applied to cover part of the original painting, not by the original artist.
Paint Layer:
One or more layers of paint between the ground and varnish layers.
Patina:
A yellowed varnish or changes in the paint layer over time, contributing to the artwork's overall appearance.
Pentimento:
A change made by an artist during the course of completing artwork.
Percussion:
The tapping of a picture to detect cavities in the ground, paint layer, or varnish.
Pigment:
A color-producing material embedded in a binding agent.
Plain Weave:
A common weaving pattern in canvas where one thread alternates under and over the warp threads.
Powdering:
The release of pigment grains in powder form due to damage or deterioration of the binding agent in the color layer.
Puncture:
A small hole or tear through the painting.
Raking Light:
Lighting cast at a low angle from the side, producing elongated shadows. Often utilized in restoration photography to highlight surface irregularities such as lifting.
Scraping:
Abrasion resulting from repetitive contact with a sharp object or tool, leading to the removal or loss of one or more material layers.
Sight Edge:
The visible perimeter of an artwork within a frame.
Size:
An emulsion, gel, or solution applied to canvas or other support material before the application of a ground layer. Size serves to protect canvas fibers from mediums like oil and reduces the fabric's absorbency.
Skinning:
Abrasion of original paint layers due to improper cleaning methods.
Strainer:
An additional support structure, typically made of wood with rigid corners, used to stretch a canvas.
Stretcher:
A support frame, often made of wood with adjustable expandable corners, used to stretch a canvas.
Stretcher Marks:
Lines of cracks or deformations along the inner edge of a stretcher or strainer bar on a painting's surface.
Support:
The material upon which an artist applies a ground and paint.
Surface Dirt:
Accumulation of dirt, grime, dust, soot, nicotine, or other contaminants on an artwork's surface.
Tabby Pattern:
Also known as "Plain Weave" (see above).
Tacking Margin/Tacking Edge:
The perimeter of the canvas wrapped around the support (stretcher), secured in place by staples or tacks.
Tear:
Damage to paper or fabric resulting in irregular or ragged edges.
Tenting:
Lifting of paint or ground and paint layers, causing them to protrude upward in a tent-like shape.
Twill Weave:
An intricate weaving pattern creating a diagonal texture.
UV Fluorescence Microscopy:
A technique involving the stimulation of examination areas to fluoresce with ultraviolet radiation under a microscope, aiding in the identification of specific substances.
Vacuum Table:
Also referred to as Heat/Vacuum Table (see above).
Varnish:
A solution of resin dissolved in a solvent that dries to form a transparent film. Typically applied as a final surface coating to saturate colors, protect paint, and provide uniform glossiness.
Warp:
Distortion or bending of the support structure of an artwork, such as canvas or paper, often due to changes in humidity or temperature.
Wear:
Changes to the artwork's surface resulting from abrasion.
Wetting Agent:
A synthetic or natural liquid that reduces the surface tension of water or other liquids. For example, a wetting agent enables other liquids to penetrate cavities in a damaged paint layer.
Wrinkles:
Furrows, ridges, or puckers occurring in a paint or varnish film during the drying process.